The George W. Bush presidential library will be dedicated on April 25th after raising more than $500 million from donors it has not (and may never) publicly identify. Corporations, governments, foreign nationals, and pretty much anyone with a checkbook can give unlimited amounts of secret money. There’s no need to wait until a president’s out of office to kick in cash, and fundraising usually starts with a few years left in office.

This situation is ripe for scandal, which is funny, because there’s been a bunch of them.

In July 2008, a Times of London reporter videotaped a Houston businessman close to George W. Bush offering access to senior White House officials to a person he thought was former central-Asian dignitary in return for a $250,000 library donation (and lobbying fees).

Former financier Marc Rich, convicted in the biggest tax evasion case at that time and illegally trading with Iran during the oil embargo, was pardoned by Bill Clinton after his ex-wife gave a $450,000 donation to his presidential library.

President George H. W. Bush pardoned Edwin L. Cox Jr., who committed bank fraud, and less than a year later Bush’s presidential library received a 6 figure donation from Edwin L. Cox Sr., the felon’s father.

Because the libraries are not required to disclose their donors, or how much they give, we cannot know how often these conflicts arise. A bill in Congress would fix that.

The Presidential Library Donation Act of 2013, introduced by Rep. John Duncan (R-Tenn.), would require quarterly online reporting of contributions over $200. The legislation enjoys strong bipartisan support and already has been reported out of the House Oversight and Government Reform committee.

Similar bills have been introduced since 2001, with a Democratic-lead measure in the 110th Congress coming the closest to enactment. It passed the House and was referred out of the relevant Senate committee only to be held up on the floor by Sen. Ted Stevens, who wanted to exclude President George W. Bush from disclosure requirements, likely at the Bush administration’s request.

President Obama should be in favor of the legislation, as he had called on presidential libraries and foundations to make public all their donors during a primary debate with Hillary Clinton in September 2007.

It’s a quirk of history that presidents fundraise for their libraries. As this Philanthropy Roundtable article explains, for most of American history, presidential papers were viewed as the personal property of presidents, and were often destroyed or split up. It wasn’t until the start of the 20th century that some presidents tried to keep all their papers together by creating private libraries.

Only in 1978 did Congress declare that presidential papers are public property, partly as a reaction to Watergate. But to avoid making the public pay the costs of these paper mausoleums, starting with George H. W. Bush, presidents who wished to have a library were obligated to raise part of the cost. According to this GAO report, presidential foundations and the government negotiate an agreement whereby library administration and remaining construction costs are borne by the National Archive and Records Administration. President Obama must raise 60% of the costs of his facility, a higher percentage than his predecessors, as this CRS report details.

Occasionally, the names of a few donors are released. George H. W. Bush had top donors inscribed in stone in the entrance to his library. Bill Clinton released the names of some contributors when his wife was up for confirmation as Secretary of State before the Senate. But with people writing $5 million checks and huge contributions from foreign countries, this is hardly sufficient.

Firstly, donor names should be required to be disclosed. Relying on voluntary disclosures means that the rules are flexible and there are no consequences for omission. The public has a need to know this kind of information.

Second, donor names should be online in a machine-readable format. Making paper copies available at a distant library at 10 cents a page is a laughable form of transparency. We easily should be able to take the donor names and compare them against lists of pardon-seekers, lobbyists, and campaign-donors.

Finally, donor names should be disclosed in a timely fashion. George W. Bush has been out of office for five years, and the corruption-deterring value has attenuated with time’s passage. Being able to see whether there’s a relationship between donation and presidential action is invaluable. While we would prefer even more frequent reporting, the Duncan bill’s requirement of quarterly reporting is a huge step forward.

Presidential libraries are the wild west of presidential fundraising. It takes place when presidents are the least accountable and involves tremendous amounts of secret money. Now’s the time to fix this loophole.